Effect of depression on all-cause mortality in adults with cancer and differential effects by cancer site

ObjectiveThe objective of this study was to compare the effect of depression on the risk of death in adults with and without cancer and by specific cancer site among those with cancer.Research Design and MethodsWe analyzed data on 10,025 participants in the population-based National Health and Nutrition Examination Survey (NHANES) 1 Epidemiologic Follow-up Study. Four groups were created based on cancer and depression status in 1982: (a) no cancer, no depression (reference group; no CA, no DEP); (b) depression but no cancer (DEP, no CA); (c) cancer but no depression (CA, no DEP); and (d) cancer and depression (CA+DEP). Six CA sites were defined: lung, breast, gastrointestinal (GI), genitourinary (GU), skin and other. Cox proportional models were used to calculate adjusted hazard for death for each group compared with the reference group and by cancer site.ResultsOver 8 years (78,433 person-years of follow-up), 1925 deaths were documented. The mortality rate per 1000 person-years of follow-up was highest in the CA+DEP group. Compared to the reference group, the hazard ratios (HRs) for all-cause mortality were as follows: CA, no DEP: 1.43 [95% confidence interval (95% CI)=1.23–1.67]; DEP, no CA: 1.44 (95% CI=1.28–1.63); CA+DEP: 1.87 (95% CI=1.49–2.34). HRs for depression by site were as follows: lung: 1.30 (95% CI=0.49–3.99); breast: 1.27 (95% CI=0.58–2.79); GI: 1.47 (95% CI=0.58–3.75); GU: 0.93 (95% CI=0.50–1.74); skin: 1.07 (95% CI=0.67–1.69); other: 2.13 (95% CI=0.55–8.25).ConclusionThe coexistence of cancer and depression is associated with a significantly increased risk of death, and the effect of depression on the risk of death differs by cancer site.